Manufacture of carbid.



H. L. HARTENSTEIN.

MANUFACTURE OF GARBID. APPLICATION FILED FEB. 18, 1907. RENEWED AUG. 20,1909.

Patented Jan. 11, 1910.

2 SHEETSSHEBT 1. 62';

H L, HABTENSTEIN.

MANUFACTURE OF GAHBID.

AIPLIOATIOH FILED ms. 18, 1907. RENEWED we. 20, 1900.

Patented Jan. 11,1910.

saqgm sg I I 2 sums-mm 2.

WED {STATE OFF E- 1 SIGNMENTSMEO CONTINENTAL -mvns'rmnnzp COMPANY, ornonorn, MINNESOTA;

: 1A cbnrona'rrou or MINNESOTA? v Specification-of To" all whom it mayconcern: r

Be it known that I, HERMAN L. Harmansrmnj'a cit'zen of the UnitedStates, residing atI Constantine, in the county of St. J osephand Stateof Michigan, have invented certain nexv and useful lmprovements in theManufacture of Carbitl, of which the following is a full,tclear, andexactflspecifica- .tion.

Thisinventiou relates to the manufacture of carbid; and itcoinpnsesamethod of producing'carbid in a new and advantageous I form bysubdividing molten or fluent carbid y ty e product1cn';p

into ewfidrops, portions 'or relatively small masses in suchfmanner asto preserve the surfaces formed in the subdivision of the liquidcr'fluent carbid; and itgalso comprises subdivided carbid in;theform ofrounded,- sincoih-suriaced, ,dense and homogeneous granules or bodieshaving the surface prop vertics of matter set from the liquid state; all

as more fully hereinafter set forth and as claimed;

The main use of calcium carbid is for the production of acetylene and.in making this gas it is brought into regulablecvntactwith water. Insuch contact with water it reacts to produce acetylene andhydrated limeaccording to the well knownyreaction, the.

lime tormi iga' layer on. the surfaceiofpcar bid eXPosedYtd' thetactionof the Water. "f'g'enerators are used in the k acgtylenefrom carbid,ebutin ism, cause a methodical coinparatively slop? evolution-pf gas inamounts proportioned to ,the' temporary requirements for consumptio'i.',lfo accomphshrthis end, .in some types successive portions of waterare fed to a, mfiinabcdy ofilcarbid while in others (the carbid; feedtype) successive portions pit-carbid are zintroducet'i' into a main.body-oflivatrythellatter type.- now be-- ing the inorepopii'lai. Foreither type it is necessary that: thee-material bein the form ofrelatively 'small gianules. \Vith a large mass crtlumpmt-carbid', thelayer oflimel formin' on 'thej react ngfa-ce' soon becomes so" thic astor'rendeflthe penetration of water slow and irregular with concomitant;irregularitiesiin the-production of gas and particularly'vhere temporarystoppages of operation give, thelimej time to crystallizg.

nanurac'rtmn or camera.

' Application aledrebruar 1 8 1907, Seria'l at); 358,012. Renewed August20, 1909. SerialNo. 513,888.

tors. On contacting carbid dust with water the evolved gas buoys it upand causes it to float, the dust-like particles not being sufii--ciently heavy tocounter-balance the adhering gas bubbles, thusdisturbing the normal opeiaticn of the generator.

In the ordinary methods of manufacturing calcium carbid, moltcncarbid isallowed to solidify in relatively large blocks, ingots or bodies-eitherin the furnace in which it is produced or in special ingot molds. Thecooling of these large bodies is'of course relatively slow,theexterior-solidifying before the interior, and during the coolingsegregation and crystallization take place in the interior with(levclopn'ient of relatively large crystals and distinct cleavageplanes, while blowholes, pipes and cavities are also formed, theinterior being frequently rather spongy, -pecially toirard the center.The interior portions are also softer and less dense in texture than theexterior; andfor some reason, but possibly because of segregationphenomena, are usually richer in gas producing carbide. In producing thecommercial carbid these blocks or ingotsare broken or crushed and thefragments sized to produce the different commercial sizes of granules.In crushing the hard, flint-like material an inordinate "amount of dustis produced, this dust coming largely from the soft and rich interiorportions. As stated, this dust is, however, practically useless, bein awaste product, and its production not on iy adds to the expense ofmanufacture but is detrimental to the health of the workmen.- Nor,without the use of special methods, can

it be remelted and converted once more into block carbid. The granulesof carbid made in this manner being fractured fragments of a. large, andfrequently highly icrystalline, mass" containing relativelyjlargecrystals, are angular,. rough -s urf faced andsharped gedgthe fracturestending'to fol-low crystal planes and line of cleavage,-a nd they expo eset and-harden, must, how-= I a "large surfaceeomparison to their volumeso that the wastage by atmospheric deterioration' in storage and handlinis large. Furthermore, having been produced by crushing, the granulesare cracked, fissured and shattered so that they tend to break downmechanically in handling, .while the.

fissures and cleavage planes oii'er avenues for the penetration ofmoisture, both from the air and in the generator, which interi-Orly-oxidizes and expands the carbid, causing the granule to crumbledown. In the generator, the angular fragments pack more or less and inthe carbid feed type of generator, they are difficult to feedmechanically without elaborate and powerful mechanism. For this reasonthe use of relatively small carbid feed generators has not proved verypracticable. lhe sharp-edged fragments are also inconvenient in storageand shipment since they tend to cut or wear through package wallsthereby not only exposing the contents of a drum or package toatmospheric deterioration but generating gas and endangering life andproperty.

In the present invention, I have devised a way of obviating thediiiiculties and waste of the described process of producing granularcarbid and have also devised a new form of carbid better adapted forpackaging, handling and use. the carbid after it has set to a flint-likehardncss, as is usually done, I perform the comminution while the carbidis still molten, soft or plastic.

By subdividing molten carbid into molten drops or portions, thesubdivision may be .accon'iplished with a minimum of labor. time andmachinery while there can be no material production of fines where theoperation is properly conducted. Where the subdivision is accomplishedby forming drops and allowing these a period of free fall throughair orgas sutlicient to insure solidification prior to collection, the carbidassumes globular or rounded forms very advantageous for the presentpurposes. Ball-like granules of carbid are readily collected, sized,packaged, stored and handled; and the various'operations may be carriedthrough without allowing any'substantial contact of the material withmoist air. In the ordinary methods of comminuting crushing and grinding,contact with ordinary air is of course practically unavoidable.

in a carbid ball or sphcre, the surface exposed for atmospheric attackas compared with the volume is of course at an absolute minimum; andsuch surface, moreover, in carbid produced according to the'prcscutinvention presents peculiarities which render it comparatively resistantagainst such at-- tack. The free surface of any liquid is in a slate ofwhat is known as .surface tern, sion; and for many purposes behaves asit covered with a dense, tough skin. In

where the carbid is solidified In lieu of comminuting pre-formcd solidcarbid in" is betterto obtain a solidifyin small bodies of carbid withfree surfaces, tns eculiar dense texture remains product, and suchsurfaces of in the tinishe course also remain smooth. Furthermore,

in small pertions solidification is too rapid to permit I any ibstantialer rtallization with production of well developed crvstals orsegregation and the granules are therefore dense and homogeneous. Whilethe mass in such a solidified portion may perhaps be re arded ascrystalline or cryptocrystalli'ne in 'c iaracter, it is not crystallinein the sense of having any \vell-(leveloped or definite crystals, beingmore stonelike in character. And, not being exposed to any crushingaction, the granules are not fissured orcracked. In the absence offissures, cracks or cleavage planes no avenues'are ofifered by which airor moisture can enter, either in storage or in thegenerator, to produceswelling oxidation products and crumble down the granuleinto ust.

The subdivision of the molten carbid may be accomplished by anyconvenient means; and the product obtained'may be balls, globules,grains, nodules, pellets, threa'ds,-shrds or filaments thisdependingupon the means employed; sohdificationfof these drops by giving them aperiod of free fall through airpr gas is however very advantageous andgives a product having man important advantages. The sphericity of the.roduct will de end upon the period of fall prior tosolidification, butin any event the product-will, be rounded and devoid of angular edges.It

granule as nearly globular as may be.

With these dense, hard, homogeneous, smooth-surfaced, rounded orball-like granules of carbid the operation of the acetylene generator isrendered much more convenlent, regular and certain. Access of a certainamount of moisture to the carbid in the carbidstorage reservoir of .thegenerator ractically cannot be avoided, but with the hard-surfaced,uncracked and unfissured homogeneous granule devoid of crystal planes,this moisture cannot enter intoithe nterior'of anygranule and crumble itdawn;

into dust to im ball-like granu es with their smooth, hard surfaces rolland feed readily,

feeding as readily as so much shot. WVith the ordinary ide theoperation. And the he formation-of drops and the sharp-edged, ragged,irregular fragments of crushed carbid, a,carbid-feed generator re quiresspecial and particular types of mechanism for feeding and thesefragments are very apt to pack and bridge across delivery. openings; adifficulty evitable presence of limeldust from enumbled lumps. With .thenew type of carbid granule, simple feed mechanisms may be employed inlieu of theirelatively comph accentuated by the incated apparatus now inuse and it is practicable to employ as small an apparatus as may bedesired. In water-feed generators the new type of carbid is alsoadvantageous as giving a more regular evolution of gas because of themore regular shape.

The molten carbid employed in producing the new form may be made in anyof the usual ways and from any of the usual materials; its particularcomposition or source not being important in the present invention.

It is tapped from the furnace or other place of production in the usualmanner and is thereafter subdivided while still molten or plastic, itbeing advantageously still freely fluid during such subdivision. Thesubdivided portions are allowed to solidify while out of contact, orsubstantially out of confor some purposes, but this specific embodimentof the present invention is not. herein specifically claimed, it formingthe subject matter of another and copending application, Ser. No.358,013, filed Feb. 18, 1907.

An advantageous method of operation is to perform the subdivision in amanner analogous to that adopted in making drop shot, the molten carbidbeing allowed to fall down a shaft under such thermal conditions that itpreserves its fluidity suiticiently long to form spherical or roundeddrops prior to solidification. No cushioning body of water can beemployed of course and though other and inert liquids may besubstituted, still they are not necessary and are often disad\-'antageous. The carbid is sutticiently high melting to become hard andsolid on reaching the. bottom of a moderately -low shaft or tower".However, upwardly directed drafts of air or' gas may be employed tocushion and prolong the fall of the drops if desired. such drafts alsooperating to prod-nee amethodical and desirable type of cooling withinthe tower.

The atmosphere within the tower or the aeriform fluid used forthe upwardblasts is not a matter of. indifference, but even with ordinary air ashort period of opera tion is suflicient to free itof harmful n1oistureand gases. It is advantageous however to use a gas poor in oxygen and itmay be high in carbon if desired.

Another method consists in subjecting -fall-ing or streaming "moltencarbid to a blast of "air or gasdirected therethrough.

This results in dispersing or soatteringthe molten mass in the form-ofdrops or filaments; the form and size depending upon the thermalconditions of gas and carbid, upon the velocity of the blastand theamount of carbid, etc. It is better to regulate the conditions to obtainrounded or spherical balls, pellets or nodules. filaments and shreds notbeing as desirable as the rounded shapes which will roll easily in thegenerator. The operation should be performed in a closed chamber andshould be so conducted, in the present specific embodiment. of this in.'ention, that the particles, drops, portions or bodies are-not onlysolid when collected but are substantially devoid of surfaceadhesiveness or stickiness.

Still another advantageous method com prises depositing the moltencarbid on a re volving table whence it will be" thrown radially outwardunder centrifugal force as drops or globules. By regulating the speed ofthe table and the feed of the molten carbid, the s'imeof these dispersedbodies will also be regulated. The higher the speed, with molten carbidof given temperature, the smaller the pellets formed. The operation maybe facilitated by the action of cooling and cushioning blasts of air or,gas fed radially outward in the path of the flying carbid, as by passingoutward from orifices or the like in the center of the revolving table.The top of the revolving table may be stepped into annular steps, orotherwise sloped, like a cone pulley, allow- 100 ing the dischargedportions of carbidto pass downward as well as outward. The revolvingtable is best mounted in a closed, air-tight casing which may beprovidedwith a hopper at its base for receiving the 105 solidified carbidgranules. An intermediate revolving body may be employed to keep thegranules in motion and prevent their sticking together in the finalstages of solidification.

The granules however produced are sized and packaged in the usualmanner.

In the accompanying illustration l have shown, more or lessdiagrammatically, certain types of apparatus of'the many adapted 115 foruse in performing the described process.

In this showing:I*-i ure 1 is a central vertical section of one form ofapparatus, shown partly broken away; Fig. 2 is a similar view of amodified form; and Fig. 3 is 1-20 a similar section of a different typeof apparatus.

Referring first. to theshowing of Fig. 1, l is a car of a suitable formand material to adapt it to transport molten cal-bid from the 125 placeof production. the car being shown as a tilting ladle car of ordinaryshape traveling on track 2 and dumping carbid into tunnel or hopper 3.Below'this hopper is mounted revolving table-A mounted 1 30 on hollowshaft 5 deriving motion through pulley 6 or other suitable means. Pipe 7allows introduction of air or gas from a suitable source (not shown)into the hollow shaft under pressure. At its upper end the hollow shaftis closed by a coned cap 8, provided with side openings or perforations9 so located and arranged as to permit air or gas jets to pass outwardradially across the table, assisting the centrifugal action in thedispersion of the molten carbid as subdivided portions. Below therevolving table is'mounted a fixed cone 10 surrounded by a rotatablehopper-shaped bottom plate or element 11, this element extendingsomewhat beneath the cone and being provided with annular flange 12..Scraper element 13 serves to direct the solidified granules to conveyer14, carrying them to suitable sizing and grading machinery (not shown).Rotation of the hopper-shaped bottom plate is accomplished by mountingit upon rollers 15, supported upon a circular track 16, and providing itwith annular gear ring 17, actuated by gear 18 on a shaft 19 which isprovided with pulley 20. Annular sidewall 21 fitting down into thehopper bottom and top 22 serve to exclude the air and to prevent loss offlying carbid.

In the structure shown in Fig. 2, the table 24 is provided with a seriesof steps, orifices or ports 25 being provided to dischar e air or gasopposite the horizontal part of each step. The rotating element is ofeourse hollow and is supplied with air or gas through shaft 26. In thismodification, the cone of the previous figure is omitted and the hopperbottom is extended centrally around the shaft, fitting at its base intodischarge conduit 271. Otherelements are the same as in Fi 1. f

In l ig. 3 is shown an apparatus permitting the formation of carbidpellets by direct free fall, molten carbid being allowed to pass throughsizing sieve 28 mounted at the top of tower 29, the carbid coming fromladle car 30 through hopper 31. At various points along the length ofthe tower are mounted upwardly directed blast pipes 32, introducingcushioning and temperature regulating jets of air or gas. 1 i

In the operation of the structure of Fig. 1, the molten carbid fallingon'the top of the rotary table is thrown outwardly as drops or smallbodies by centrifugal action or by centrifugal action aided by theradial gas or air jets, and falls as solid balls or pellets upon theconed elements 10 and 11, down which it rolls to the bottom, whence itis removed by thefeonveyeri' 'VVith a slow rotation of the table, theforce of the gas jets may be depended on to disrupt and disperse themolten carbid flowing over its edge. The operation of Fig. 2 is the samesave that the carbid pellets fall successively over degree desirable bthe edges of the stepped elements of the table. In Fig. 3, the moltencarbid passing through the sieve is converted into drops and thesesolidify in their progress downward, such progress being retarded to anythe upwardly passing jets of air or gas rom twyers 32, such jets alsoserving to control the temperature differential between the top andbottom of the tower so as to insure solidification in rounded bodies orshot form. v

'In the illustration, for the sake of simplicity of showing, the variouselements are represented only diagrammatically, refractory linings,heating means-and the-like being omitted as unnecessary in explainingthe principles involved in this invention.

What I claim is 1. As a new article of manufacture, calcium carbid inthe form of detached individual solidified substantially non-angular androunded particles.

2. As a new article of manufacture, calcium carbid in the form ofdetached separate solidified particles.

3. As a. new article of manufacture, calcium carbid in the form ofdetached pellets.

4:. As a new article of manufacture, caltiur'i carbid in the form ofseparately cooled 5. As a new article of manufacture, calcium carbid inthe form of detached solidified globules.

6. As a new article of manufacture, calcium carbid in the form of smalldetached,

*lidified particles, having smooth, noncryzstalline and non-angularsurfaces.

mass of carbid com osed of small individual As a new article ofmanufacture, a

particles, each suc particle possessing the I properties of a dropstate.

8. As a new article of manufacture, a mass of calcium carbid composed ofsmall individual particles, each such particle possessing the propertiesof a drop set from the molten state.

9. In the manufacture of carbid, the process which comprises disntegrating such carbid into a multiplicity of relatively small articleswhile such carbid is hot and plastic.

10. In the manufacture of calcium carbid, the process which comprisesdisintegrating calcium carbid into a multiplicity of relatively smallparticles while such carbid is hot and plastic.

11. As a new article of manufacture, calcium carbid in the form of aplurality of small detached particles, each such particle having roundedsurfaces and being substantiall free of well developed eystallizationand of exterior or interior lines of cleavage. a

12. '1 he method of converting molten calcium carbid into particleswhich comprises set from the molten fluid under pressure, and allowingthe scattered particles produced to solidify.

15. The method of subdividing carbid into" small particles, whichcomprises forming molten carbid into drops and allowing the drops tosolidifytut of contact with each other.

1G. The method of converting calcium earbid into particles whichcomprises subdividing the mass of carbid while in the molten state intosmall particles and allowing the particles to cool in the presence'of a'gas out of contact with solids.

17. The method of converting a' carblcl into particles which comprisessubdividing the mass of carbid while .in the molten state into smalldrops and allowing the drops to cool while in suspension and out ofcontact with solids and each other. i

- 18. The method of converting calcium carbid'into small particles whichcomprises subdividing a mass of carbid while in the molten state intodrops or globules and allowing the drops or globules to solidify out ofcontact with solids or limids.

19. The method of sub-dividing calcium carbid into small particles whichcomprises forming molten carbid into small drops or globules andallowing said drops or globules to 0001 out of contact with one another.

20. As a new article of manufacture, calcium carbid in the form of amass of small, rounded, dense, homogeneous, smooth-surfaced particles,the surfaces of such particles having the properties of surfaces setfrom a molten state.

21. As a new article of manufacture, calcium carbid in the form of amass of small, substantially spherical, dense, homogeneoussmooth-surfaced particles, the surfaces of such particles having theproperties of surfaces set from a molten state.

22. As a new article of manufacture, calcium carbid in the form of around, homogeneous, dense, substantially non-crystalline,smooth-surfaced body, the surfaces of such body having the properties ofsurfaces set from a molten state.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, on this 16th day of February A.D. 1907.

HERMAN L. HARTENSTEIN.

